Temperature control apparatus



Oct. 10, 1944. A. F. scHuMANN :TAL

TEMPERATURE CONTROL APPARATUS FiledfApril 15, 1943 sheets-sheet 1 IN VEN TORS A 1 FRED E S CHU/144 AWA/va 0t- 10, 1944 y A. F. svcHUMANN ET AL2,360,167

TEMPERATURE CONTROL APPARATUS Filed April 15, 1943 4 2 sheets-sheet 2 aINVEN T0125 l b ALFRED /Scm/MANNA Nc BY L ExA/vpE/'Qd TURF/N l Il? APatented Oct. 10, 1944 UNITED STATES PATENT QFFICE TEMPERATURE CONTROLAPPARATUS Application April 15, 1943, Serial No. 483,118

1 Claim.

The invention relates to the control of the temperature prevailingwithin a combustion chamber, more especially to a chamber red by reachesits minimum limit of regulation, a further control is brought intooperation by which a cooling medium is automatically applied to reducethe temperature the desired extent.

A further object of the invention is to provide an automatic controlmeans which will effect regulation as well of the burner, the aforesaidcooling medium applying means being maintained ineffective until suchtime as a burner operating means has attained its minimum limitposition.

In carrying out the invention, a suitable burner is provided fordischarge into a combustion chamber, said burner being provided with theusual or special means for regulating the volume 'of combustibleconsumed by the burner between a maximum and a minimum value. Inaddition, provision is made for cooling as in providing the chamber withan admission opening for a gaseous cooling medium such as air, whichopening is designed to be controlled for regulation of the volume ofadmitted air.

In accordance with the invention, there is associated with the aforesaidburner regulator means and with the means for controlling admission ofair or like gaseous medium, a temperature responsive element and motormeans controlled thereby, said motor means being designed to operate apulley system. The latter, in turn, is connected with the operatingelement of the burner and also with the means for controlling thecooling medium, for example, a closure door or damper for the opening tothe chamber. The pulley system to this end includes a movable pulleyunit flexibly connected with the motor means for reciprocation thereby,said movable pulley having a cable running thereover, one end of `whichis connected over a xed pulley to a p-redetermined mass and the otherend over a second fixed pulley to a greater mass, both being suspendedfrom the cable. The first-named connecting portion of the cable also isattached to the burner operating element to cause the same to moveangularly in the regulation of the burner in accordance with thereciprocation of the cable portion, while the second-named connectingportion of the cable is attached to regulating means for the coolingmedium, for example, to cause said medium to be applied or interruptedin accordance with the reciprocation of said lastnamed cable portion.Due to the relation of the two masses attached to the said respectiveends of the cable portion, the lighter mass will be the rst to rise withmovement of the movable pulley unit as the motor means operates under.

the influence of the temperature-responsive element in a direction toreduce the volume of combustible from the burner. When this combustibleregulation attains a position for minimum supply of combustible, stopmeans will be engaged which will prevent further movement of the burneroperating element in a direction to reduce volume of combustible.

The lesser mass will therefore no longer be elevated and continued pullon the pulley unit by the motor means will cause the heavier mass torise, thereby operating the means regulating the cooling mediumsufficiently to reduce the temperature such that the responsive elementactuating the motor means will cause the latter to reverse the directionof movement of the movable pulley unit.

The nature of the invention, however, will best be understood whendescribed in. connection with the accompanying drawings, in which:

Fig. 1 is a fragmentary front elevation of a heating chamber withattached burner and airadmission door, together with the automaticallyoperating means for regulating the operation of said burner andair-admission door.

Fig. 2 is a fragmentary longitudinal section of the heating chamber andair-admission door, with burner shown in elevation and the automaticallyoperating means omitted. 1

Fig. 3 is a perspective View indicating more o less diagrammatically theautomatically operating means in position of maximum volume ofcombustible supply to the burner.

Fig.y 4 is a similar View with the various elements in their respectivelocations for operation of the burner under minimum supply oflcombustible, while Fig. 5 illustrates similarly the elements in theirrespective` locations for operation of the burner under minimum supplyof combustible and with introduction of a cooling gaseous medium.

Referring to the drawings, more especially Figs. 1 and 2, lil designatesa suitable combustion chamber whose temperature it is desired tomaintain at a predetermined maximum value or through it the temperatureof a mixture or bath I I in a vessel I2 through a pair of communicatingpipe coils I3 and I4 respectively in the combustion chamber I6 and thevessel i2. The ccmbustion chamber is heated by discharging thereinto theproducts of combustion and/or name of a burner I5 of any well-known orspecial construction designed for variation, between limits, oi thevolume of combustible. Such a burner may, for example, be of tltnatureof the proportional burner set forth in U. S. Letters Patent Nos.

2,219,119 and 2,290,785 granted applicants assignee. Burners of thisnature are operatedior regulation of the volume oi combustible sup-plyusually through the oscillation or" an angularly movable element or armI6 between two positions as determined by suitable stops or lugs il andI8, respectively, the former being that for vmaximum supply of thecombustible and the vlatter that for minimum supply thereof, all ofVwhich is well understood and formsnoparticulai part of the presentinvention.

Provision is made, however, to further control Y the temperature of thelcombustion chamber and/or the coil I3 therein by the introduction of acooling medium, in the particular embodiment `atmospheric air, which isintroduced through an opening I9 located, for example, below the burner.The location of this opening, however, may be rvaried to suit theparticular conditions and various constructions of heating chambers.Nor- .mally, opening I9 is designed to be closed by a door 2li hinged at2I so as to be capable of swinging outwardly to afford various areas ofopening Vfor the introduction of air into the interior of i the chamberI0.

It will be understood that during the normal operationV of the heatingchamber, door 2D will remain in its position to close the opening I9 andthe regulation of the temperature within the heating chamber I0 will beeffected solely by' properly positioning the element IS. f "Inaccordance with the invention, this is to be Aaccomplished automaticallyand by the same mechanism whereby further regulation (lowering) of thetemperature is attained should the control effected by movement of theelement I6 be insumcient to hold the temperature to the `predeterminedmaximum when element I6 has reached its minimum regulating position.This necessitates, in the rst place, a control system subject to thetemperature prevailing within chamber I0, or, in the case of theembodiment hereindescribed, the temperature of the bath I I, whichsystem maycomprisea heat-responsive member as a thermocouple 25. lThethermocouple in turn being responsive to such temperatureis caused toactuate through a suitable controller means 26, as is well understood, amotor Vmeans f 21 which is connected, as hereinafter set forth, througha pulley system, with the element I 6 and also with a bracket 28extending outwardly from Ythe door 20.

The pulley system for securing this connection to the two regulatingelements for control of the temperature includes a movable pulley unit3B the other portion 3S of the cable running over a` lixed pulley 40.

The operation of the control system is indicated in the diagrammaticrepresentations, Figs. 3 to 5. Fig. 3 illustrates the location of thevarious members at normal operation with maximum supply Aof combustibletothe burner I5, the regulating arm I6 thereof being then in its extremeleftvhand position as limited by the lug or stop I l. When Vthetemperature within the vessel I2 attains the desired predeterminedvalue, or the temperature suddenly rises, in the case of an exothermicreaction occurring in connection with the heating of a mixture, thetemperature control hereinbefore described will operate in manner wellunderstood to move said arm towardV the minimum position through thecable connections which connect it to the arm 32 of the controllersystem. Weightr33 is elevated thereby, allowing of this angular movementof arm I 6, but the weight 35, being of greater mass, will retain itsposition. This continues until arm I6 engages the lug or stop I8, and ifthis reduction in supply of combustible is insuicient to reduce theinte-v rior temperature of chamber IU to `the required degree, it willbe apparent that other means must be provided to effect a reduction asthe burner is of the continuously operating type with no shut-01T atminimum regulating positions, Ath'us avoiding the necessity for ignitioncontrols and the like. In Fig. 4 this minimum position of the regulatingarm IS-is indicated and it will be noted that the weight 35 stillretains itsposition and that the weight 33.has been elevated`aporresponding distance, indicated at' (a), above the position formaximum supplyof combustible.

By the time arm I6 assumes its position of minimum regulation, furtheroperation of ...the controller arm 32,in the direction for reduction oftemperature will begin to elevate theweig-ht 35. This results from thefact thatfarmY I6,-in engaging with the stop I8, introducesan inniteresistance with respect to the weight'33 whereby the continued pullon'pulley 3takes effect on the portion 36 of the cable and causes weight35 to rise to the extent'of the travel of saidLpulley 30. The extent ofthis elevation is indicated at (b), Fig. 5, and the cable portion' 36,being connected with the closure member 20, movesthe same about therhinge 2| Yto uncover the opening I9 and allow atmospheric air to beintroduced therethrough to the interior of chamber I0 and elect therequired cooling.

We claim:

The combination with a heating chamber having a burner Vfor' fluidcombustible discharging thereinto, said burner being provided withcontrol means for'regulating the volume Ofcombustible and includingstops to limit saidmeans between a'maximum andaminimum operating value,the said chamber having also an opening for admission of a coolingmedium, together with control means for regulatingk the area -o saidopening; Jof means for operating the two 'said control means of the saidchamber, comprising a temperature-responsive element and NVmotor meanscontrolled thereby, and akpulley system including a movablepulleyconnected withjthe motor means to be reciprocated thereby,together with a cable running over the movable pulley, one portionthereof passing over a Xed pulley and having suspended from its end apredetermined mass and the other portion passing over a second' xedpulley and having suspended from its end a greater mass, said. rst-namedconnecting portion of the cable being connected with the burner controlmeans and the second-named connecting portion with the cooling mediumad- 10

